In the automobile manufacturing industry, automobiles are generally manufactured through a plurality of processes, such as a body process (main and metal), a painting process (paint), an assembly process (trim), and a final test process (final). Inside each of those processes, respective stations are interconnected by rails, and vehicles are moved at equal intervals and at a constant speed, while a work load and a work time are different for each process. For increasing efficiency of an overall production line, it is required to decide a work sequence in the various processes without causing an extra vehicle to stand by between the processes and causing a change in the vehicle sequence, for example, so that respective lines constitute one continuous line.
Hitherto, a decision on a building sequence capable of meeting conditions in all the processes at the same time has been made based on manual work of a skilled person in charge of planning, because the decision requires specific know-how.